A voice service of a Long Term Evolution (LTE) network is referred to as a Voice over LTE (VoLTE) service. Currently, more operators start to apply VoLTE for commercial use, and more user terminals can support a VoLTE service. Media data of a VoLTE service is carried on a user plane dedicated bearer in an LTE network (currently, it is defined in a standard that a dedicated bearer whose quality of service class identifier is equal to 1 is used). Generally, a requirement of a VoLTE service for LTE network performance is higher than that of a data service.
In an existing mechanism, a VoLTE service creation process is implemented mainly according to whether resources of a cell are sufficient, and when the entire cell still has resources that can satisfy VoLTE, a dedicated bearer of a VoLTE service is established. However, in some scenarios, a VoLTE service established based on the existing mechanism is poor in stability, which sometimes severely affects call experience of a user.